The vast majority of integrated circuits today are sold in sealed packages, such as molded plastic resin packages. Although some of these packages may leak or outgas to some extent, the sealed packages protect the integrated circuits contained therein from stress and damage. Examples of these packages include ball-grid array packages, flip-chip packages, dual in-line packages, and quad-flat-packages.
Many integrated circuits require other devices to operate. For example, a microprocessor device may require access to a memory device. Typically, these devices can be placed on a printed circuit board and connected, or integrated, on a single substrate as described in U.S. Pat. No. 5,031,092 to Edwards, incorporated by reference herein.
U.S. Pat. No. 6,699,730 to Kim et al. and U.S. Pat. No. 6,708,132 to Gutierrez et al., both incorporated by reference herein, disclose multiple semiconductor chips provided in a single integrated circuit package. Such devices are typically referred to as multi-chip modules (MCMs). Other MCMs provide multiple sealed packages on a substrate, which are then mounted onto another substrate, such as a WL1141 Integrated PHY Module commercially available from Agere Systems, Inc.
Integration of different types of devices while still keeping the size of the module small, however, can be difficult. Different devices can require different materials to operate, and these devices cannot be integrated together. Other devices are fragile or difficult to produce and are preferably not combined with devices that are more robust or easier to make, as that would lower manufacturing yield. For example, U.S. Pat. No. 6,635,509 to Ouellet, incorporated by reference herein, discloses wafer-level packaging of a MEMs device. Such a device is difficult to produce with a high-yield. Some devices can be modified after they are manufactured to satisfy a particular need. For example, U.S. Pat. No. 5,952,890 to Fallisgaard et al., incorporated by reference herein, discloses a programmable oscillator.
Consistent with an aspect of the present invention, different types of devices are integrated in a small package. Such integration is achieved by providing an integrated circuit package that combines a sealed device with a semiconductor chip.